1. Field of the Invention
The present invention relates to hydraulic tools and, more particularly, to a hydraulic tool having a mechanical actuator.
2. Brief Description of Prior Developments
U.S. Pat. No. 5,979,215 discloses a hydraulic compression tool with a rapid ram advance. The tool comprises a mechanical actuator which can directly push against a rear end of a ram. The ram is separately movable relative to the mechanical actuator. A bypass valve is provided in the conduit system of the tool to allow hydraulic fluid to bypass the mechanical actuator. The bypass valve is located spaced from the mechanical actuator.
There is a desire to provide a hydraulic compression tool which has additional space within its main body, but without increasing the size of the main body. There is also a desire to permit a bypass valve for a hydraulic compression tool to be relatively precisely adjusted external to the tool. There is also a desire to provide a hydraulic compression tool bypass valve as a subassembly. There is also a desire to reduce complexity of the hydraulic conduit system in the main body of a hydraulic compression tool.
In accordance with one aspect of the present invention, a hydraulic compression tool is provided having a frame, a hydraulic fluid reservoir on the frame, a ram movably connected to the frame, a conduit system in the frame between the reservoir and the ram, a pump provided in the conduit system, a mechanical actuator provided in the conduit system for contacting the ram, and a bypass valve in the conduit system between a rear end of the ram and a channel of the conduit system to the rear end of the mechanical actuator. The conduit system is adapted to conduit fluid from the pump against both the rear end of the ram and a rear end of the mechanical actuator. The bypass valve is located, at least partially, in a housing member of the mechanical actuator.
In accordance with another aspect of the present invention, a hydraulic compression tool mechanical actuator is provided including a housing member and a bypass valve. The housing member has a front end adapted to push against a hydraulic compression tool movable ram, a rear end hydraulic fluid pushing surface, and a hydraulic fluid conduit channel through the housing member. The bypass valve member is connected to the housing member at the conduit channel.
In accordance with another aspect of the present invention, a hydraulic compression tool is provided having a frame, a hydraulic fluid reservoir on the frame, a ram movably connected to the frame, a conduit system in the frame between the reservoir and the ram, a pump provided in the conduit system, and a mechanical actuator provided in the conduit system for contacting the ram. The conduit system is adapted to conduit fluid from the pump against both the ram and the mechanical actuator. The conduit system comprises a single hydraulic fluid suction line extending from the reservoir. Hydraulic fluid from the reservoir is deliverable through the single suction line directly to the ram through a check valve and, to the mechanical actuator through the pump.
In accordance with one method of the present invention, a method of manufacturing a hydraulic compression tool is provided comprising steps of providing a mechanical actuator assembly, the mechanical actuator assembly having a housing member with a hydraulic fluid channel therethrough, and a bypass valve located in the housing member at the channel; connecting the mechanical actuator assembly to a frame of the tool, the frame including a conduit system, the housing member of the mechanical actuator assembly being slidingly located in a portion of the conduit system; and connecting a ram to the frame. The ram is movable on the frame and is adapted to be directly contacted by the mechanical actuator assembly. The ram is movable relative to the housing member of the mechanical actuator assembly.
In accordance with another method of the present invention, a method of advancing a ram in a hydraulic compression tool is provided comprising steps of actuating a pump of the tool to move the ram relative to a frame of the tool at a first rate of movement by pushing hydraulic fluid against a first pushing surface of a mechanical actuator to push the ram forward, the mechanical actuator being located against the ram; and actuating the pump to move the ram relative to the frame at a second slower rate of movement by pushing hydraulic fluid against a second larger pushing surface of the ram to push the ram forward. The mechanical actuator has a conduit channel with a bypass valve therein. The step of actuating the pump of the tool to move the ram relative to the frame at the second lower rate of movement includes hydraulic fluid passing through the conduit channel and the bypass valve of the mechanical actuator to the second larger pushing surface of the ram.